Method of making plaster board



Aug. 31,1926. 1,597,990 I J. F. MAKOWSKI METHOD OF MAKING PLASTER BOARD Fi July 1925 2 Sheets-Sheet 1 INVENTOR .lEMLkOU/Sk?) J. F. MAKOWSKI METHOD OF MAKING PLAS'IEH BOARD Filed Jul 16, 1925 -2 Sheets- Sheet 2 INVENTOR J; i jlfalwwsla Patented Aug. 31, 1926.

UNITED STATES JOHN F. MAKOWSKI, OF STOCKTON, CALIFORNIA, ASSIG-NCR TO CALIFORNIA CEDAR iii-97.9% PATENT OFFICE.

PRODUCTS COMPANY, OF STOCKTON, CALIFORNIA, A CORPORATION.

METHOD OF MAKING PLASTER BOARD.

Application filed July 16, 1925.

This invention relates to'the art of making wall board, the present invention being directed especially to the method of handling the wall board after it is first formed to properly stretch, set and dry the same.

My invention is used in the making of that type of wall board wherein a center plastic core of plaster and sawdust is rolled between two surface sheets of paper to a desired thickness to form the wall boards. These boards are usually and preferably made up one quarter of an inch thick, thirty six to forty eight inches wide and in lengths of four to twelve feet.

One of the problems confronting the manufacturer in making boards of this material is to get it made and dried without marrinp; the surface, having it wrinkle or buckle or showing surface stains or discolorations.

When the wet plastic mass is rolled between the dry sheets of paper the paper absorbs moisture therefrom and tends to stretch across its width. If this stretch is r not uniform the paper will wrinkle and the surface of the boards will not be smooth.

If the stretch is uniform when the plaster sets it holds the paper in its stretched position so that the surfaces of the board are smooth and true.

The drying of the board after theplastic mass has set has usually heretofore been accomplished by setting the board on edge between spacing stakes and introducing them into a kiln. In the type of board made by me this results in stains and discolorations on the face of the board where the spacing stakes touch the same. This renders the board commercially objectionable. Also unless great care is exercised the board is apt to warp or become wavy, which condition is likewise objectionable.

These objections I aim to overcome by the method of handling the board herein F shown, described and claimed.

Serial No. 43,936.

mechanism whereby the formed and stretched board may be suspended in spaced relation to allow it to dry.

Fig. 3 is a perspective View of a suspen- S1011 clamp showing a fragmentary portion of wall board therein.

Referring now more particularly to the characters of reference on the drawings the letter A designates generally the board forming and handling mechanism of any desired type but preferably of that type shown in my pending application for Patent 1Segigal No. 682,48 filed December 24th, I94

.By this mechanism the wall board 1. is formed into its initial wet unset condition, which constitutes the first step in my process.

The next step in the process consists in laying the wet, unset board on a smooth and flat plane surface as on the smooth floor of a truck or carrier 2 where it is allowed to remain a suflicient length of time to allow the wet paper covering sheets to attain their maximum stretch and the plastic mass to set. Then the next step of the process is to thoroughly dry the board and it is desirable to do this in such a way as to leave the board smooth and unwarped and without spots or blemishes on its exterior surface. This is done by drying the board in suspended and spaced relation and I preferably accomplish this in the following man ner:

I first elevate the carrier 2 by means of block and tackle 3 so as to lift the board.- into substantially vertical position. A clamp 4 is then clamped to the upper edge of the board and by means of a swiveled lever hook 5 the clamp and board is swung to suspended position from one of a number of spaced hooks 6 on a carriage '7 capable of being moved into a kiln or other drying area 8.

In order to keep the soft and tender wet board from tearing down when suspended it is absolutely necessary that the suspension be a complete pivotal one so as to prevent the weight of the board from pulling against any one point on the board. To that end a special form of clamp is a necessity and I therefore preferably use one constructed as shown in detail in Fig. 8. I have two parallel boards held together by spring clips 4 to frictionally engage the top edge of the board along its complete length. Central of each board is secured a small plate 4 having a relatively large orifice 4 Into these orifices are freely and loosely engaged hooks 4 on the free ends of -a suspension hook l which, in suspending the board, is engaged with one of the :hooksfi- It will thus be seen that the board is able to adjust itself so that the suspended weight will pull equally against the upper edge of the board. Thus it will not tear or warp as it d'rys' bu't will be perfectly true and straight. Since the boards aresuspended in spaced relation nothing touehes their surfaces so they are free from discoloration or blemish.

I am aware that the prior art discloses the idea of suspending wall board to dry the same. Such uses as have come :under my observation however encompass the idea of feeding the wall board as lllitCle continuously directly into the clamps and to suspended position Without laying same on a smooth surface for a period of time to take its stretch. I have found that this is absolutely necessary, since under the former method the tight 1 clamp holds the edge of the paper from stretching and "the balance of the paper will try to stretch after the board is suspended and this Will-cause the surfaces of the board I claim.: 1. 'The process of making wall board of the type described consisting in forming the board, laying the board on a smooth fiat surface until the paper cover sheets have attained their limit of stretch, then suspending the board and drying it while suspended.

2. The process of making wall board consisting in forming the board, allowing the paper cover sheets to :attain their full limit of stretch, :and -then suspending the board and allowing it :to dry while suspended.

3. The process of :making wall board of the character described consisting in forming the board, allowing the paper cover sheets to :attain their full limit of stretch, securing a clamping element alongone ifree -edge of-the boardand suspending'the clamp- :ing element at its center 'to have a full and free pivotal movement in 'all directions.

ln testimonywhereof I'afix my signature.

JOHN :F; MAKOWS'KI. 

